In X, a drawable is an object into which you can draw, either a window or pixmap. ProXL drawing procedures take an argument of type "Drawable". Therefore, you can pass either a window or a pixmap to these drawing procedures.
ProXL extends this concept to include displayables, screenables, windowables, colormapables, gcables, and fontables. If, for example, a ProXL procedure requires a screen as an argument, you can pass either a screen or any other object which uniquely determines a screen. One object can uniquely determine another in two ways, either directly or via a default. For example, a window is directly associated with only one screen. Therefore, anywhere a screen is required any window associated with that screen can be specified. On the other hand, a display may have more than one screen associated with it, but it has only one default screen. Therefore, anywhere a screen is required the screen's display can be specified, if the display's default screen is the screen in question.
Following is a complete listing of the -ables supported by ProXL. The parenthesized associations below indicate that unique determination is made via a default value.
Therefore, subsequent sections in this manual may describe an argument of a ProXL procedures as, for example, a GCable. In this case you can specify either a window, pixmap or GC as the argument.